Synthesis and characterization of mesoporous materials containing cerium, lanthanum and praseodymium by nonhydrothermal method

摘要

Mesoporous molecular sieves the type MCM-41 (Mobil Composition of Matter of number n) modified with rare earth elements cerium, lanthanum and praseodymium (CeMCM-41, LaMCM-41 and PrMCM-41) was synthesized via direct and nonhydrothermal method at 80 A degrees C and characterized by X-ray diffraction, nitrogen absorption (BET/BJH), thermal analysis (TG/DTG), infrared spectroscopy (FT-IR), scanning electron microscopy, transmission electron microscopy and acidity measurements. The catalytic activity of the synthesized catalysts was tested in an esterification reaction of oleic acid with methanol. The reaction was carried out at 130 A degrees C with an alcohol/acid molar ratio of 8 and 5 wt% catalysts for 2 h. Among all of the catalysts tested in this study, the most efficient was LaMCM-41 affording over ca. 37 wt% of conversion. Hence, the catalyst LaMCM-41 was used for the detailed study on the effect of any reaction parameters such as acid/alcohol molar ratio, temperature and reaction time to obtain the conditions for maximum conversion.